package ThreadDemo;

import java.util.ArrayList;

public class Test {
    public static synchronized void main(String[] args) {
        ArrayList<Integer> list = new ArrayList<>();
        Thread t1 = new Thread() {

            public void run() {
                for (int i = 0; i < 10000; i++) {
                    synchronized (list){
                    list.add(i);
                    }
                }

            }
        };
        Thread t2 = new Thread() {

            public void run() {
                for (int i = 0; i < 10000; i++) {
                    synchronized (list) {
                        list.add(i);
                    }
                }
            }
        };
        t1.start();
        t2.start();
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {

        }
        System.out.println(list.size());
    }
}